Erik Jones <erik(at)myemma(dot)com> writes:
> One very important thing to note here is that the number, or rather
> rate, of disk writes has not changed. It's the volume of data in
> those writes that has dropped, along with those transaction
> mysterious counts.
Hmm. I'm suddenly thinking about the stats collector: in existing 8.2.x
releases it's got a bug that causes it to write the collected-stats file
much too often. If you had done something that would shrink the size
of the stats file, that might explain this observation. Do you have
stats_reset_on_server_start turned on?
The drop in reported transaction rate is still baffling though. Are you
sure you're really doing the same amount of work? Can you estimate what
you think the transaction rate *should* be from a what-are-your-clients-
doing perspective?
regards, tom lane